Backlight modules are classified into direct type backlight modules and edge type backlight modules according to different positions of light sources. In a direct type backlight module, light sources are directly arranged below a light emergent surface, and light generated by the light sources is emitted out as a surface light source after going through a spatial distance and being diffused and mixed by a diffusion plate; in an edge type backlight module, light sources are arranged on side faces of the backlight module, and light generated by the light sources is emitted into a light guide plate. The light guide plate can atomize linear light sources or point light sources into a uniform surface light source, then the light emitted from the light guide plate is diffused and deflected by a diffusion plate, and finally the divergence angle of the light is adjusted by a condenser lens.
FIG. 1 is a structural schematic diagram of an edge type backlight module in the prior art, FIG. 2 is a partially enlarged schematic diagram of structure Z in FIG. 1, FIG. 3 is a schematic cross-sectional view taken along A-A direction in FIG. 2, FIG. 4 is a structural schematic diagram of a reflector plate in FIG. 1, and FIG. 5 is a structural schematic diagram of a light guide plate in FIG. 1. As shown in FIGS. 1-5, the backlight module includes a backplane 1, a reflector plate 2, a light guide plate 3 and an LED light bar 4, wherein both of the reflector plate 2 and the light guide plate 3 are in the shape of rectangle, and the reflector plate 2 is located below the light guide plate 3; the LED light bar 4 includes a base 402 and an LED light 401 fixed on the upper surface of the base 402; a fixing adhesive tape 5 is formed on an area of the upper surface of the base 402 without LED light 401 covered thereon and on the upper surface of the backplane 1; and the fixing adhesive tape 5 is used for fixing the base 402 to the backplane 1.
However, when the base is fixed to the backplane through the fixing adhesive tape, the fixing adhesive tape will occupy a certain area, resulting in an increased width of a frame part of a display device. Meanwhile, since the LED light will produce heat in a light emitting process, the fixing effect of the fixing adhesive tape is instable. More importantly, when the backlight module needs to be reworked, residual adhesive is likely to be left on the backplane, which increases the difficulty of subsequent treatment. In addition, since the net point distribution area at two vertex angles β on the light guide plate is relatively small, enough brightness is unlikely to obtain through sufficient scattering, and meanwhile, the distances from the vertex angles to the closest LED light on the LED light bar are relatively large, so that the brightness at the two vertex angles β on the light guide plate will be obviously smaller than the brightness of other positions on the light guide plate, resulting in a dark corner on the display device in a display process to influence the display effect of the display device.